All of us who have supervised for a while have probably handled these situations in ways that we wish we could have done differently. But our dumb tax is what helps us figure out what not to do in the future.
There is no perfect way of handling situations like this but here are some things to think about.
We are often tempted to try to paint the resignation in a rosier fashion than is warranted, both to save face for the ministry and the one who is leaving. It is good to be gracious always in our communication. However, if it is well known that there has been either conflict or a problem, messaging the leaving in a rosy fashion can come across as disingenuous to those who know better. In that case it is better to be factual - than to write something that is not true.
Resignations can be problematic both for the ministry and for the one leaving. The first thing I do in these cases is to have a candid discussion with the one leaving as to the implications of how both sides handle the transition. In a ministry, how we handle transitions comes down to not hurting the work God is doing even if we feel we have been ill treated. For a staff member in a church to seek to divide the church in their anger is to hurt the bride of Christ, not a wise thing to do regardless of how we view the circumstances.
The discussion should start with the question, "What will honor God as we walk through the transition?" I have watched staff member handle themselves with great honor and others who have handled themselves with amazing dishonor. How we handle these situations is really a reflection of our character. To the extent that we can control the situation we want to honor God in the process.
If there is bad blood it is wise to sit down with the one leaving and talk about the implications of what both sides say. If you plan to give a severance package it is always a wise thing to tie that severance package to an agreement as to what each side is going to communicate. There is no place for trashing one another in the process and the employer has some pull in that they can tie a severance package to a legally binding agreement as is done in business all the time.
Where there is a belligerent attitude on the part of the one departing, it is fair to say to them that you intend to be gracious in your response - but that if they choose to trash the ministry on the way out that you reserve the right to be more forthcoming in response if necessary to the questions that will come from those whom the employee has communicated with. That gives them an incentive to be circumspect in what they say.
It behooves the ministry to be as generous as they can be when there is a problematic resignation. Whether we like it or not, people have a constituency and their constituency will often take up their offense. You do not need to be apologetic for doing the right thing but one does want to be able to show grace and care in the process.
This also goes to helping the individual, where appropriate, with finding another job through an outside service. Again, a generous spirit is far better than a stingy one, even if one thinks that the staff member does not deserve it.
Often a staff member will ask for several months so that they can find another job. If the resignation is problematic this is not a good idea because the awkwardness of the situation will inevitably affect the rest of the staff. It is better to agree to paying them for a period of time but ask them to spend their time looking for another job and not continuing on in their current role in the process. I have tried it. It rarely works.
In churches there is often a belief that the congregation needs to know everything. Not only is that a foolish thing to do but it is very easy to open yourself up to legal liability by disclosing certain information.
Again, an HR professional can keep you from making a misstep here. I strongly advise that any communication that is made is run by either an attorney or HR professional in today's litigious environment. I have actually seen staff members who are leaving, whether forced or not, bring their attorneys to church business meetings to see what is or is not being said.
Finally, leaders should be wise but not intimidated by a staff member that is intent on hurting the ministry on the way out. That behavior is actually proof that you have made the right decision.
What we aim for is a process that honors the ministry, the individual leaving and the people of God.